Six people were arrested in connection with the assassination of presidential candidate Fernando Villavicencio in Ecuador on Thursday and a seventh was shot dead by police officers, AFP reported.

All the suspects are Colombian, according to the police.

Describing the killing as "a political crime of a terrorist nature," Ecuadorian Interior Minister Juan Zapata said that the police will continue investigating and seeking a motive for the crime.

Villavicencio, a 59-year-old journalist and a critic of corruption and organized crime, was killed in an armed attack following a political rally in the capital Quito on Wednesday night.

The involvement of Colombian nationals in the murder is reminiscent of the 2021 killing of Haiti's President Jovenel Moise, who was assassinated in his home by a group which included 26 Colombians and two Haitian-Americans.

Following the assassination, President Guillermo Lasso declared a two-month state of emergency, and wrote on social media that he had "requested the support of the FBI" with the investigation into the murder.

Lasso also declared three days of national mourning.

(With input from agencies)